Generalisation of ephemeris for SBAS support.

Author: gsmcmullin

include/libswiftnav/constants.h

@@ -25,6 +25,8 @@
 #define R2D (180.0 / M_PI) /**< Conversion factor from radians to degrees. */
 #define D2R (M_PI / 180.0) /**< Conversion factor from degrees to radians. */
 
+#define DAY_SECS (24*60*60) /** < Seconds in a day */
+
 /** \defgroup gps_constants GPS
  * Constants related to the Global Positioning System.
  * See ICD-GPS-200C.

include/libswiftnav/ephemeris.h

@@ -23,21 +23,40 @@ typedef struct {
   double crs, crc, cuc, cus, cic, cis;
   double dn, m0, ecc, sqrta, omega0, omegadot, w, inc, inc_dot;
   double af0, af1, af2;
-  gps_time_t toe, toc;
+  gps_time_t toc;
+  u8 iode;
+} ephemeris_kepler_t;
+
+typedef struct {
+  double pos[3];
+  double rate[3];
+  double acc[3];
+  u8 iod;
+  u16 toa;
+  u8 ura;
+  double a_gf0;
+  double a_gf1;
+} ephemeris_xyz_t;
+
+typedef struct {
+  gnss_signal_t sid;
+  gps_time_t toe;
   u8 valid;
   u8 healthy;
-  gnss_signal_t sid;
-  u8 iode;
+  union {
+    ephemeris_kepler_t kepler;
+    ephemeris_xyz_t xyz;
+  };
 } ephemeris_t;
 
-s8 calc_sat_state(const ephemeris_t *ephemeris, gps_time_t t,
+s8 calc_sat_state(const ephemeris_t *e, gps_time_t t,
                   double pos[3], double vel[3],
                   double *clock_err, double *clock_rate_err);
 
-u8 ephemeris_good(ephemeris_t *eph, gps_time_t t);
+u8 ephemeris_good(const ephemeris_t *eph, gps_time_t t);
 
 void decode_ephemeris(u32 frame_words[3][8], ephemeris_t *e);
-bool ephemeris_equal(ephemeris_t *a, ephemeris_t *b);
+bool ephemeris_equal(const ephemeris_t *a, const ephemeris_t *b);
 
 #endif /* LIBSWIFTNAV_EPHEMERIS_H */